United Kingdom European Union membership referendum, 2016

A referendum on continued United Kingdom membership of the European Union is scheduled to take place in the UK and Gibraltar on 23rd June 2016. The UK government, an official "Remain" campaign and other groups and some political parties support UK membership, while an official "Leave" organisation and other "out" groups, including the UK Independence Party, are campaigning for the country to exit the EU. Many other organisations, including corporations and small businesses, have also expressed opinions one way or the other on the prospect of a UK departure.

The campaign has so far focused on the economic consequences of staying or leaving, as well as immigration. "Leave" campaigners have argued that a UK outside the EU will be be able to freely negotiate lucrative free trade deals, while the "Remain" camp has warned of an economic downturn and isolation. In April 2016, the USA appeared to strongly back the status quo when President Barack Obama told voters that exit would place the UK "in the back of the queue" in terms of cutting a free trade deal with America, because the focus would be on an upcoming US-EU deal.

As of April 2016, opinion polls indicate that the two sides are roughly tied, but the results are disputed. Polls have been found to give different results depending on whether they are carried out by phone or on line. The government has indicated that in the event of an exit vote, a two-year departure process under the Lisbon Treaty will begin soon after the result.

Although the government collectively supports remaining, collective responsibility has been suspended, allowing five cabinet ministers and some junior ministers to campaign openly for leaving. The House of Commons is roughly 3 to 1 in favour of remaining and the Confederation of British Industry, representing mainly big business, about 4 to 1. There is more support for leaving among small businesses, though still a minority. Most major trade unions are also in favour of remaining, as is the Church of Scotland; the Church of England is thought unlikely to take sides. Most economists likewise support remaining.

It is estimated that something around 7,000,000 people theoretically entitled to vote will be unable to do so because they are not on the electoral register in spite of a publicity campaign and the extension of the deadline after the computer system crashed.